How to add more PWM IOs to Pixhawk for servo control

Hi all,

I am a new Pixhawk user and need your support/advice for PWM IO extension.

The VTOL design requests 20 PWM channels (8 motors, 2 wings, 4 elevon, 4 flaps, 2 rudder) but Holybro Pixhawk 4 provides only 19. I am pleased receiving your design recommendation solving this issue.

Pixhawk 4 Interfaces:
8-16 PWM outputs (8 from IO, 8 from FMU)
3 dedicated PWM/Capture inputs on FMU


Hi, I don’t know the clear answer.

But haven’t you considered using Y cables for servos? Create groups that move the same way (Join 2 rudders into 1 group, 4 flaps into 2 groups, 4 elevons into 2 or 1 group).

Make sure there is enough power for so many servos.